Conventionally, there is provided a power cord including a plug connected to a power socket, a temperature sensor for detecting the temperature of the plug, and a shut-off device for stopping the power supply to a load from the plug when an abnormal temperature rise is detected by the temperature sensor (see, e.g., Japanese Unexamined Patent Application Publication No. H7-67245). The plug has a plurality of plug pins, each being inserted into the power socket and brought into contact and conduction with a pin rest in the power socket.
According to the power cord of this type, even when abnormal heat generation occurs because of a contact failure of the plug pins of the plug at the power socket, fire or damage to the plug due to the heat can be prevented by stopping the power supply.
In a case where only one temperature sensor is provided, a correlation between the output of the temperature sensor and the temperature of the plug pin farthest from the temperature sensor among the plurality of plug pins becomes relatively low. Accordingly, response to the temperature rise at the corresponding plug pin becomes slow, and safety may be reduced.
On the other hand, in a case where a plurality of temperature sensors is provided and the output of each temperature sensor is monitored individually, it may cause an increase in the number of parts and/or complication of a wiring.